Effect of smoothing reactor on the performance of a PWM chopper fed Dc motor drive

This paper presents the qualitative change in the speed response of a pwm dc/dc converter fed series motor drive system due to different choices of values for smoothing reactor. In particular, a detailed investigation on bifurcation behavior of motor speed has been performed for identifying the permissible range of the smoothing reactor for desired stable period-1operation of the drive system over a wide zone of load torque. With only speed loop operative and assuming the system to be in continuous conduction mode, investigation is performed by numerical simulation of the drive system. Experimental investigations are also performed on a 500 watt, 220 volt, 1800rpm dc series motor to study qualitative behavior of motor speed for different values of smoothing reactor.